CONTROLLING METHOD OF SOLUTION CONCENTRATION AND BATH LEVEL OF TREATING BATH CELL GROUP IN CONTINUOUS TREATING LINE

摘要

PURPOSE:To control simultaneously the soln. concn. and bath level of each cell group by calculating the balance equation of the soln. concn. and bath level between the respective treating bath cells, substituting the variation of the amt. and concn. of the soln. therein and calculating the soln. feed and charge of the raw liquid, etc. beween the treating systems. CONSTITUTION:The bath level and soln. concn. of each treating liquid system are inputted into an arithmetic device 7 from the level gages 2a-2d and concn. meters 3a-3d of respective circulation tanks A-D in a continuous treating line for a steel strip. The amt. of the soln. in each tank is calculated by the device 7 and the change rate is calculated by comparing the same with the amt. of the soln. in the initial state. The feed and the charge of the raw liquid and water between the respective adjacent treating bath cells are calculated in accordance with such change rate as well as the initial concn. and the measured concn. value. Control signals are outputted to respective pumps 5 and flow control valves 6 in accordance with the results thereof to operate the pumps and valves for the necessary time. The basic unit of the soln. is reduced by such control.